Bruno Domenjoud 1, Sylvie Baig 2, Santiago Esplugas 1 1 Department of Chemical Engineering, University…

Bruno Domenjoud1, Sylvie Baig2, Santiago Esplugas1

1Department of Chemical Engineering, University of Barcelona, Spain. 2Degrémont SA, France.

Biotreated urban wastewater effluent treatment by oxidative and adsorption technologies

Paris, May 25, 2011, IOA-IUVA World Congress

20th IOA World Congress Paris, FRANCE, 2011.

OUTLINE

Introduction Advanced treatment

Ozone and AOPs _ Fundamentals

GAC & PAC _ Fundamentals

Study Objectives

Experimental

O3 treatment

AC treatment

Process comparison

Conclusions2


Why advanced treatment of wastewaters? Improvement of water quality Wastewater reuse: increase of water availability

ADVANCED TREATMENT

3

Objective : Sustainable use of water Answer to water shortage Minimization of environmental and health risks

New challenge : Emerging micropollutants removal

Metallic or organic substances present in very low concentrations in the environment and that may have a toxic action at small concentration.

• Pharmaceuticals & Personal Care Products (PPCPs)– Cytostatic agents, immunosuppressive drugs– Human and veterinary antibiotics– Natural and synthetic hormones– Halogenated compounds such as iodinated Xray contrast media– Heavy-metal containing drugs and non-therapeutic medical agents

• Pesticides• Domestic and Industrial chemicals and their by-products

– Detergents: nonylphénols, alkylphenols – Biocides– Packaging, various composite materials: PVC, Bisphenol,

phthalates– Flame retardants: Polybrominated ethers (PBDEs), polychlorinated

biphenyls and polychlorinated terphenyls (PCBs)– Combustion Products: PAHs, dioxins

Approximately 63 000 chemicals are in common use worldwide.200 to 1 000 new synthetic chemicals enter the market each year.

EMERGING MICROPOLLUTANTS

► Priority Hazardous (13)► Priority (20)PentaBromodDiphenylEthersDiEthylHexylPhtalatesPentachlorobenzene Chloroalcanes C10-13NonylphenolsOctylphenolsFluorantheneAlachlorChlorfenvinphosChlorpyrifosDiuronIsoproturon Tributyltin & cpds

1,2-DichloroethaneTrichloromethaneTrichlorobenzenes HexachlorobenzeneHexachlorobutadieneHexachlorocyclohexanePentachlorophenolCadmium and cpds Mercury and cpds

► Hazardous (8)DDT, DDD, DDEAldrineDieldrineEndrine IsodrineCarbon tetrachloridePerchloroethylene Trichloréthylène

Priority substances WFD 2000/60/CE

List I Hazardous substancesdirective 76/464/CE

PAHsAnthraceneEndosulfanNaphthaleneNickel and cpdsLead and cpds

List II Hazardous substancesdirective 76/464/CE (139)

DichloromethaneBenzeneAtrazineSimazineTrifluralin

ChlorobenzeneChloroprène3-chloroprene1.2-Dichlorobenzene1.2-Dichlorobenzene1.4-Dichlorobenzene1.1-Ddichloroethane

EthylbenzeneToluene1.1.1-Trichloroethane1.1.2-TrichlorethaneVinyl ChlorideXylenes…

EMERGING MICROPOLLUTANTS

ADVANCED TREATMENT MICROCONTAMINANTS REMOVAL

Useful Mechanisms– Key parameters

• Volatilization through mixing and aeration– Henry’s Law constant (volatility)

• Adsorption onto suspended solids and sludge– Octanol Water partition coefficient

(hydrophobicity)• Biological degradation

– Solubility, size, structure (biodegradability)

• Photodegradation at water surface– UV absorption

• Chemical oxidation– Structure, type and dose of oxidant

• Molecular rejection– Molecular weight, molecular length

and length, steric hindrance, charge, octanol water partition coefficient

Advanced treatment

• Biological processes with high sludge retention time– N & DN– MBR

• Membrane filtration– Nanofiltration– Reverse Osmosis

• Activated carbon• Chemical oxidation

– Ozonation– AOPs

Need to treat the concentrate and waste

Need to evaulate both the fate of the parent compounds as well as conjugates and bioactive by-products


Name E° (V)

Fluor 3,03

Hydroxyl radical 2,80

Ozone 2,07

Hydrogen peroxide 1,78

Potassium permanganate 1,68

Standards redox potentials (298 K, H2)

O3 AND AOPs _ Fundamental notionsMoxidized

O3

HO·

M

InitiatorsPromoters

M M’oxidized

Inhibition

Molecular O3 attack is selective : attack on high electronic density sites.HO· attack is much more unselective : few compounds resist to its action.

Initiators Promoters InhibitorsHydroxide ions

Hydrogen peroxideUV254 radiation

Heterogeneous catalystsOrganic matter

OzoneHydrogen peroxide

Organic Matter

Hydrogen peroxideCarbonates

Organic MatterTer-butanol

7


GAC_ Fundamental notions

8

breakthrough curve

time

Fixed bed operation

* Porous material

* Non destructive treatment

* Equilibrium “Langmuir equation”

break point

saturation point

active zone


OBJECTIVE OF THE STUDY

Specific objectives Organic micropollutant removal,

Evaluation of OM removal,

comparison between O3 and AC.

Contribute to a better knowledge on advanced technologies able to improve the quality of the water discharged from WWTPs, both considering the conventional parameters and emerging contaminants.

9


EXPERIMENTAL _ Material & operating conditions

10

CatalyticreductionO3 gas analyzer

O2

P

O3 generator

Air vent

Reactor

Pressure valve

O3 gas analyzer

PAir ventT

P

Trap of KITraps of

NaOH 2M

O3 liquidanalyzer

pH sensor

CatalyticreductionO3 gas analyzerO3 gas analyzer

O2

P

O3 generator

Air vent

Reactor

Pressure valve

O3 gas analyzer

PAir ventT

P

Trap of KITraps of

NaOH 2M

O3 liquidanalyzer

pH sensor

O2

P

O3 generator

Air vent

Reactor

Pressure valve

O3 gas analyzer

PAir ventT

P

T

P

T

P

Trap of KITraps of

NaOH 2M

O3 liquidanalyzer

pH sensor


11




Ozonation general operating conditions and system parameters

12

Ozone operating parameters In operation Inlet ozone gas phase concentration 10 - 40 Ng/m3 Inlet gas flow rate 60 - 100 NL/h Reaction temperature 20 ºC Sample volume 1 - 2 L Reaction pH Not adjusted Ozone system parameters

Reactor type Stirred tank reactor

Hydrodynamic behavior Completely mixed liquid Non-plug-flow for gas

Global mass transfer coefficient (Kla) 0.25 min-1



13

1 m3

Feedingtank

PINLET

OUTLET

1 m3

Feedingtank

PINLET

OUTLET



14

GAC adsorption general operating conditions and system parameters

GAC operational parameters In operationFlow type Down-flowFlow rate 80 L/hLoading rate 11 m/hGAC height 0.60 mEmpty Bed Contact Time 3.3 minPAC & GAC parameters

Supplier Chemviron CarbonCarbon type Granular Filtrasorb F400PAC Effective sizeGAC Effective size

8 - 25 μm 0.6 - 0.7 mm

GAC Density 0.47 g/cm3

Sewage water

Sandfiltration

Microfiltration

Reverseosmosis

Brine

DischargeReuse

Discharge

Discharge

Sewage water

Pre-treatment

MBR Ultrafiltration

Discharge

Primary and secondary treatments Tertiary and advanced treatments lines

ABDC

EXPERIMENTAL

Sewage water

Biofilter

Secondaryclarifier

Activatedsludge

Pre-treatment


EXPERIMENTAL _ Material and Methods

Chemical Oxygen Demand

Biological Oxygen Demand

Dissolved Organic Carbon

UV-Absorbance at 254 nm

Suspended Solids

Turbidity

Inorganic Carbon

pH

Nitrate and ammonia content

Conventional parameters

Analytical parameters

Micropollutant analysis

VOCs

PAHs

PBDEs

OLCs

Pesticides

Phtalates

Octylphenols//nonylphenols

Organic matter fractionation

LC-OCD-ON-UVA16


17

Fraction Molecular weight Description

Biopolymers >> 20,000 DaPolysaccharides and proteins.

High molecular weight, hydrophilic and non-UV absorbable.

Humic substances ≈ 1,000 Da Calibration based on Suwannee River standard from IHSS.

Building blocks or humic-like

substances350 – 500 Da Breakdown products of humic

substances.

Acids and low-molecular weight

humics< 350 Da Aliphatic and low molecular weight

organic acids

Low-molecular weight neutrals < 350 Da

Weakly or uncharged low molecular weight compounds as

well as low molecular weight slightly hydrophobic compounds

LC-OCD ANALYSIS


EXPERIMENTAL _ Effluent characteristics

SampleName Origin

DOC COD COD/DOC BOD5 SUVA pH IC NH3 turbi SS

mgC/L mgO2/L mgO2/mgC mgO2/LL/

(mg·m) mgC/L mgN/L NTU mgSS/L

A1 SF 8.1 45 5.6 n.q. 2.5 7.1 8 n.q. 1.4 1.7

A1 SF+MF 7.4 15 2.0 n.q. 2.4 6.6 11 n.q. 0.1 n.q.

A2 SF 6.7 29 4.3 < 1 1.8 8.1 65 < 1 7.8 n.q.

A2 SF+MF 6.5 19 2.9 < 1 1.8 6.6 16 < 1 0.3 n.q

A3 SF 12.9 77 6.0 n.q. 1.6 6.6 95 38 29.5 n.q.

A3 SF+MF 9.8 29 3.0 n.q. 1.7 6.9 49 36 0.5 n.q

[A4] SF+MF 5.4 18 3.3 n.q. 2.3 5.2 n.q. n.q. 0.1 n.q.

A5 SF+MF 13.2 50 3.8 n.q. 1.9 8.5 52 n.q. 0.1 n.q.

A6 SF+MF 7.5 27 3.6 n.q. 1.9 8.0 46 6 0.1 n.q.

B1 PF 13.9 45 3.2 3.2 2.2 7.9 29 29 n.q. n.q.B2 PF 18.2 58 3.2 n.q. 2.4 8.0 13 34 n.q. n.q.C UF 6.3 26 4.1 1.4 2.0 7.5 n.q. < 0.1 0.1 n.q.D LF 6.0 23 3.8 3.2 1.4 6.6 15 < 2.5 1.3 6.2

oxidation parameters physical parameters

Best quality using MBR-UF and LFSimilar DOC- different COD because Turb and SS

Low aromaticty (<2)Low biodegradabilty BOD/COD<0.14


19

HOC BIO-polymers Humic Sub-

stances

Building Blocks

LMW Neutrals LMW Acids0

10

20

30

40

50A1 _ SF A1 _ SF+MF

A2 _ SF A2 _ SF+MF

A4 _ SF+MF D _ LF

DO

C re

parti

tion

(%)

EXPERIMENTAL _ Effluent characteristicsLC-OCD Analysis

Differences between HOC and humic substances

HOC = highly hydrophobic substances

BIO-polymers HOC + Humic substances

Building Blocks LMW Neutrals LMW Acids0

10

20

30

40

50

60 A1 _ SF A1 _ SF+MF

A2 _ SF A2 _ SF+MF

A4 _ SF+MF D _ LF


20

EXPERIMENTAL _ Effluent characteristicsmicrocontaminants depends on effluent, day, etc..

A4 SF+MF

0200400600800

10001200140016001800

Raw values (ng/L)

0102030405060708090

A4 SF+MF


0.00

0.20

0.40

0.60

0.80

1.00

0 25 50 75 100 125 150 175 200 225

CO

D/C

OD

0

Time (min)

A1 _ SFA1 _ SF+MFA2 _ SFA2 _ SF+MFA3 _ SFA3 _ SF+MFA5 _ SF+MFA6 _ SF+MFB1 _ PFC _ UFD _ LF

21

O3 TREATMENT

Filled symbols correspond to presence of SS and turbidity

good COD removal in all cases

Fastest COD removal en presence of SS due to the oxidation of the OM matter attached in the COD which is mainly hydrophobic and thus highly ozone reactive


0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 25 50 75 100 125 150 175 200

DO

C/D

OC

0

Time (min)

A1 _ SF+MFA2 _ SFA5 _ SF+MFA6 _ SF+MFB1 _ PFC _ UFD _ LF

22

O3 TREATMENT

Filled symbols correspond topresence of SS and turbidity

ozone is able to lead to 40 to 70 % of OM mineralization

dissolution of particulate organic matter(OM attached to the SS)


23

O3 TREATMENT

0123456789

10

0 30 60 90 120 150

pH

Time (min)

A2 _ SFA2 _ SF+MFB1 _ PFC _ UFD _ LF

jump of pH to the oxidation of acidic compounds of the hydrophobic fraction. Gong et al. (2008)

contribution OH· radical attack at pH >8)


0.00

0.20

0.40

0.60

0.80

1.00

0 25 50 75 100 125 150 175 200 225

UV 25

4/UV 25

4,0

Time (min)

A1 _ SFA1 _ SF+MFA2 _ SFA2 _ SF+MFA3 _ SFA3 _ SF+MFA5 _ SF+MFA6 _ SF+MFB1 _ PFC _ UFD _ LF

24

O3 TREATMENT

aromatic compounds readily eliminated during the first minutes of the reaction, from 50 to 80 %.

low removal rate

high removal rate


0

5

10

15

20

25

30

0

5

10

15

20

25

30

35

0 20 40 60 80 100

BO

D5

(mg/

L)

CO

D (m

g/L)

Time (min)

A2 _ SFA2 _ SF+MFC _ UF

0

0.1

0.2

0.3

0.4

0.5

0 20 40 60 80 100

BO

D 5/C

OD

Time (min)

A2 _ SFA2 _ SF+MFC _ UFD _ LF

25

O3 TREATMENT

COD continuously decreases

BOD continuously increasesand decreases

conversion of low biodegradable organic matter into more biodegradable compounds.

maximun valueBOD/COD reached 0.4


26

O3 TREATMENT

0

10

20

30

40

50

0

5

10

15

20

25

30

35

40

0 30 60 90 120 150

N-N

O 3(m

gN/L

)

N-N

H 3(m

gN/L

)

Time (min)

A3_SF A 3 _ SF+MF

B1_ PF B2 _ PF

Nitrogen removal which consumes ozoneNitrate formation lower than ammonia oxidated


27

O3 TREATMENT

0

500

1000

1500

2000

2500

HOC BIO-polymers Humic Substances

Building Blocks

LMW Neutrals LMW Acids

DO

C (μg

/L)

A2 _ SF+ MF (Raw sample)

A2 _ SF+MF (TOD = 21 mg/L)A2 _ SF+MF (TOD = 91 mg/L)

0

500

1000

1500

2000

2500

HOC BIO-polymers Humic Substances

Building Blocks

LMW Neutrals LMW Acids

DO

C (μg

/L)

A2 _ SF (Raw sample)

A2 _ SF (TOD = 20 mg/L)

A2 _ SF (TOD = 86 mg/L)

SF and MF

HS and LMW neutralsdecrease with ozone dose

Building blocksincreasewith ozone dose

Cleavage of high MW into lower MW substances and acid formation


28

GAC TREATMENT

0

20

40

60

80

100

0

500

1000

1500

2000

2500

3000

HOC BIO-polymers

Humic Substances

Building Blocks

LMW Neutrals

LMW Acids

Rem

oval

yiel

d (%

)

DO

C (μg

/L)

A4 _ SF (GAC inlet) A4 _ SF (GAC outlet) Removal yield

after 4 m3 (breakthrough)

90 %77 %

87 %

0102030405060708090

100

UV254 COD DOC

Ave

rage

rem

oval

yie

ld (%

)

IRO: GAC performances

0102030405060708090

100

0.0 0.5 1.0 1.5 2.0

Accumulated volume (m3)

Rem

oval

yie

ld (%

)

UV254

COD

DOC

Sampling

good removal yield for all fractions

Low removal yield for biopolymers


29

GAC treatment micropollutants removaldepends on efluent, day, treatment time, etc..

A4 SF+MF

0102030405060708090

100

good removal for all microcontaminants

after 4 m3 (before breakthrough)parameter removal %

DOC 87COD 77UV 90


0

20

40

60

80

100

7 mg/L

9 mg/L

O3 TREATMENT micropollutants removal

30

Removal yield depends on effluent and ozone dose

D MBR

stripping for some volatil compounds as trichloroethylene, benzene, etc.

good removal for all microcontaminants at low ozone dose



31

Removal yield depends on effluent and ozone dose

0102030405060708090

100

TOD = 17 mg/L

TOD = 82 mg/L

A2 SF+MF

stripping for some volatil compounds as Cl4C, trichloroethylene, benzene, etc.

good removal for all microcontaminants


0

10

20

30

40

50

60

70

80

90

100

Cl4C

Trichlor

oethy

lene

Perch

loroe

thylene

Benze

ne

Fluoren

e

Phena

nthren

e

Pyren

e

BDE-28

BDE-47**

BDE-99**

BDE-100**

BDE-209

Simaz

ine

Terbu

thylaz

ine

Chlorpi

ripho

s

A2 SF

A2 SF+MF

TOD = 17 mg/L

Sample

Name

DOC COD SUVA IC turbi

mgC/L mgO2/L

L/(mg·m)

mgC/L NTU

A2 SF 6.7 29 1.8 65 7.8

A2 SF+MF 6.5 19 1.8 16 0.3


At small O3 dose carbonates and SS do not modify the removal (results not shown)

small influence of the microfiltration in micropollutants removal


O3 _GAC TREATMENT micropollutants removal

33

SampleName

DOC COD COD/DOC SUVA pH

mgC/L

mgO2/LmgO2/mgC

L/(mg·m)

A2 SF+MF 6.5 19 2.9 1.8 6.6

A4 SF+MF 5.4 18 3.3 2.3 5.2

OZONE

GAC

0

10

20

30

40

50

60

70

80

90

100

Cl4C

Trichlo

roeth

ylene

Perchlo

roeth

ylene

Benze

ne

Fluore

ne

Phena

nthren

e

Pyrene

GAC

A2 SF+MFTOD = 82 mg/L

At high ozone dose similar removal ofmicropollutantsfor GAC and Ozone

Cost comparison - Data• COD 30 mg/L

Water flowrate 420 m3/h• Ozonation

– Dose 20 mg/L– Contact time 15 min

• Activated carbon filtration (4 filters)– Adsorption capacity 40 mg COD/g– 80% COD removal- 10 min EBCT

- Costs– Oxygen 0.06 €/kg– Electricity 0.07€/kW– Activated carbon 450 €/m3

Cost comparison

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

CAPEX k€ OPEX k€/an

Ozonation

Activated Carbon filtration

0

2

4

6

8

10

12

14

16

1 2 3 4 5 6

Number of years of depreciation

Inde

x of ann

ual g

loba

l cos

t

Activated Carbon filtrationOzonation


CONCLUSIONS

Ozonation as well as GAC filtration technologies were shown to be effective in removing from urban secondary effluents most of the micropollutants regulated by the European Directives.

At ozone doses around 20 mg/L, only the HCH were shown to be ozone recalcitrant.

Ozonation achieved effective COD, TOC and UV254 removals.

At initial times of ozonation, the micropollutant oxidation proceeds simultaneously with the conversion of non biodegradable, aromatic and high molecular weight soluble substances into more biodegradable, less unsaturated and more fractioned molecules.

Oxidation of ammonia into nitrates, which increase the ozone needs, and dissolution of attached organic matter onto SS were also highlighted from the beginning of the ozone treatments.

36


CONCLUSIONS AND RECOMMENDATIONS

Micropollutants adsorption onto GAC competes with the simultaneous adsorption of around 90 % of DOC.

High organic matter loaded would strongly limits the life time of the GAC. In consequence, effective pre-treatments are required upstream to make the GAC application suitable.

Depending on the chemical make-up of water pollution, the best technological solution can either be ozone oxidation or activated carbon adsorption. Cost comparison and Life Cycle Assessment study would draw the final selection of the best solution.

37

Bruno Domenjoud1, Sylvie Baig2, Santiago Esplugas1

1Department of Chemical Engineering, University of Barcelona, Spain. 2Degrémont SA, France.

Biotreated urban wastewater effluent treatment by oxidative and adsorption technologies

Paris, May 25, 2011, IOA-IUVA World Congress

THANK YOU FOR YOUR ATTENTION !

The authors are grateful for the financial support from the Spanish Ministry of Industry (CDTI) within the framework of the Project CENIT:

CEN20071039.

Documents

Bruno Domenjoud 1, Sylvie Baig 2, Santiago Esplugas 1 1 Department of Chemical Engineering, University…